Stackable block for insulating concrete form system

ABSTRACT

A concrete form system comprising a reversibly stackable insulating form blocks each block having a pair of panels separated by two or more ties. Each of the top, bottom and side edges of the panels includes either a tongue or groove so as to engage a corresponding tongue or groove of a panel of another block stacked vertically or horizontally adjacent thereto. The panels of each block are arranged in opposite orientation to each other so as to enable the block to be stackable in either an upside-down or right-side-up orientation.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 60/555,956 filed on Mar. 25, 2004.

FIELD OF THE INVENTION

The present invention relates to concrete form systems and, more specifically, to systems comprised of stackable foam block units. More particularly, the invention relates to insulating concrete form blocks that are reversibly stackable.

BACKGROUND OF THE INVENTION

In the field of constructing concrete walls, it is commonly known to use forms normally comprising a pair of panels arranged parallel to one another and separated by a distance. Concrete is then poured between the panels and allowed to set. After the concrete is set, the panels, usually made of wood, are removed. It is common to have ties extending between the two panels to ensure that the desired spacing is maintained.

The advent of insulating concrete form (ICF) systems has provided an improvement in concrete form systems. In ICF systems, the panels comprise slabs of insulating foam between which the concrete can be poured. Once set, the foam panels are left in place thereby providing both sides of the concrete wall with integral insulating layers. The foam panels are separated by ties that normally comprise two flange portions that are embedded in each of the opposed foam panels and a web portion extending there-between. The flanges can be embedded by forming the foam panels around them, by sliding the flanges into slots in the foam, or by any other manner as will be apparent to persons skilled in the art. The ICF systems are also available in pre-made blocks of standard dimensions that can be stacked both vertically and horizontally to create any desired configuration of form. An example of an ICF system is provided in U.S. Pat. No. 5,896,714, which shares common inventors with the present application (the entire disclosure of U.S. Pat. No. 5,896,714 is incorporated herein by reference). In this patent, a form block is disclosed having various unique features. One of the key features is that, once the blocks are stacked, the tie flanges on each side of the form (and, therefore, the concrete wall) are vertically aligned. This results in a vertically continuous nailing surface for securing wall finishing material such as vapour barriers, additional insulation, wall boards and the like.

Other ICF block systems are taught in the following U.S. Pat. Nos.: 4,229,920; 5,429,933; 6,253,523; 6,401,419; and 6,412,245 (the disclosures of which are incorporated herein by reference).

One of the problems associated with some known ICF block systems is that the blocks can only be used in one orientation. That is, they cannot be stacked above another block unless they are positioned in a specific inside/outside, top/bottom manner. This often results in wastage of product. Such wastage is particularly faced when a block is cut to a smaller size and the remaining portion cannot be used since their orientation cannot be reversed.

Some of the prior art patents mentioned above disclose blocks that may be reversed in orientation. For example, U.S. Pat. No. 5,896,714 teaches an ICF block that can be stacked in either orientation when rotated about its vertical axis. That is, the block does not have 20 a designated inside and outside face. However, this block has a specific top and bottom, depending on the first course of the blocks that are laid. U.S. Pat. No. 5,428,933, on the other hand, does teach a block that is reversible along either the longitudinal or vertical axis. However, this reference does not allow for the ties of the block to be aligned once stacked.

Thus, there exists a need in the art for a reversible ICF block that overcomes at least some of the deficiencies of the known blocks.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a concrete form block for use in a form system, wherein the block is stackable in either vertical orientation.

In another aspect, the invention provides an insulating concrete form block made of a pair of foam panels spaced apart by two or more ties and wherein the panels are provided with interlocking means to enable vertically and horizontally adjacent blocks to engage each other and an alignment means to ensure vertical alignment of the ties. The interlocking means of each panel are arranged opposite to the other of the block so as to allow the block to be reversible, or used in either vertical orientation.

In another aspect, the invention provides an insulating concrete form block comprising a pair of foam panels separated by two or more ties, wherein each of the panels has an interlocking means for engaging neighbouring blocks, and wherein the block has a first plane of symmetry extending diagonally between the top of one panel to the bottom of the other panel and a second plane of symmetry extending diagonally between the top right corner to the bottom left corner of the block. The panels of the block are provided with an alignment means to ensure vertical alignment of the ties when the blocks are stacked.

In another aspect, the invention provides a reversibly stackable insulating concrete form block, for use in a concrete form system, comprising: first and second foam panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; and two or more ties extending perpendicularly between the panels to maintain the panels in the spaced apart orientation. In each panel, its top and bottom edges and left and right ends have: a) a first interlocking means for engaging a respective panel of a block vertically adjacent thereto; b) a second interlocking means for engaging a respective panel of a block located horizontally adjacent thereto; and c) a tie aligning feature for vertically aligning ties of vertically adjacent blocks. In the block, the panels of the block are arranged in opposite orientation with respect to each other whereby the block can be engaged with other vertically adjacent blocks in either a right-side up or upside-down orientation.

In another aspect, the present invention provides a reversibly stackable insulating concrete form block, for use in a concrete form system, comprising: first and second foam panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; and two or more ties extending perpendicularly between the panels to maintain the panels in the spaced apart orientation. Each panel includes a top edge, a bottom edge, and left and right ends. Also, in each panel: a) one of the top and bottom edges includes a first tongue extending longitudinally along the edge; b) the other of the top and bottom edges includes a first groove extending longitudinally along the other edge and being adapted to receive a tongue having the dimensions of the first tongue; c) one of the left and right ends includes a second tongue extending longitudinally along the end; d) the other of the left and right ends includes a second groove extending longitudinally along the other end and being adapted to receive a tongue having the dimensions of the second tongue; e) two or more projections extending from the edge having the first tongue; and f) two or more recesses provided on the edge having the first groove. The panels of the block are arranged in opposite orientation with respect to each other whereby the top of the first panel faces the bottom of the second panel and the right end of the first panel faces the left end of the second panel.

In a third aspect, a reversibly stackable insulating concrete form block, for use in a concrete form system is provided. The block comprises first and second panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; and two or more ties extending perpendicularly between said panels to maintain the panels in said spaced apart orientation. Further, on the first panel, on its top edge there is at least one positive feature for engaging a panel of a block vertically adjacent thereto; on its bottom edge, there is at least one negative feature for receiving a corresponding positive feature of the adjacent panel. Also, on the second panel, on its bottom edge, there is a compatible positive feature to the positive feature on the first panel; and on its top edge, there is a compatible negative feature to the negative feature on the first panel. The features are located on the respective edges such that the block can be engaged with other vertically adjacent blocks in either: a right-side up orientation with the negative feature of the first panel engaging a corresponding positive feature on an adjacent panel of a block below; or an upside-down orientation with the compatible negative feature engaging the corresponding positive feature on the adjacent panel.

In other aspects various combinations of sets and subsets of the above aspects are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein:

FIG. 1 is a perspective view of a prior art form block;

FIG. 2 is an end elevation of the prior art block of FIG. 1;

FIG. 3 is a perspective view of a prior art form constructed with a plurality of form blocks;

FIG. 4 is a perspective view of a form block according to an embodiment of the present invention;

FIG. 5 is a front elevation of the block of FIG. 4;

FIG. 6 is a plan view of the block of FIG. 4;

FIG. 7 is an end elevation of the block of FIG. 4;

FIG. 8 is a rear elevation of the block of FIG. 4;

FIG. 9 is a front elevation of a tie used in forming the block of FIG. 4; and

FIG. 10 is a perspective view of an embodiment of the invention for use in a corner.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a prior art form block as described, for example, in U.S. Pat. No. 5,896,714. As shown, the block 10 comprises opposing panels 11 and 12 made of an insulating foam material as will be known to persons skilled in the art. The panels 11 and 12 are joined together by means of a plurality of ties 13 extending there-between. The panels 11, 12 are maintained in an aligned and parallel manner, with the ties 13 extending perpendicularly between the panels. As shown in FIG. 1 and as known in the art, the facing surfaces of each panel 11 and 12 are preferably provided with a plurality of grooves so as to form a stronger bond with the concrete.

FIG. 2 illustrates an end view of the block of FIG. 1 and more clearly illustrates the tongues 24 and grooves 26 of the prior art form block. FIG. 2 also illustrates the ties 13 as known in the art. The ties comprise a central, planar web portion and two flanges on opposite ends of the web portion. The flanges are embedded within the foam panels 11 and 12 and are preferably designed to extend over the entire height of each panel. In this way, when the blocks are stacked and the ties vertically aligned, the flanges provide continuous strips to which fasteners etc. may be attached.

FIG. 3 illustrates a partial form constructed with a plurality of blocks 10 arranged both horizontally and vertically (i.e. stacked) according to the dimensions of the wall required. Also illustrated in FIG. 3 is a corner block 20, which has a similar construction to the linear block 10 but includes a 90° corner. It will be understood that the corner block can include any desired angle apart from 90°. FIG. 3 also illustrates at 22, the alignment of the flanges of the ties. As discussed above, by vertically aligning each tie when the blocks 10 are stacked, the 20 flanges form a continuous vertical strip, as shown at 22, to which various types of fasteners may be secured for attaching wall coverings etc. As can also be seen in FIG. 3, the outer surfaces of the panels may be provided with features such as embossing or other such indicia as taught in the prior art to identify the locations of the flanges.

Returning to FIG. 1 once more, the panels 11 and 12 are provided with a number of features that enable adjacent blocks to engage each other so as to ensure that, once the form is erected, the blocks are maintained in position. These interlocking features comprise, firstly, a longitudinally extending tongue 24 provided on the top of each panel 11 and 12 and a longitudinally extending groove 26 provided on the bottom of each panel. The tongues 24 and grooves 26 are designed so as to permit the tongues on the tops of the panels of one block to enter into the grooves on the bottoms of the panels of an adjacent block when the blocks are stacked. This engagement serves to restrict adjacent panels from moving with respect to each other. Further, each end of the panels is provided with either a tongue or groove to engage the panel of an adjacent block. However, as shown in FIG. 1, the tongues and grooves on the sides of the panels are oppositely provided. That is, on one side of the block, one of the panels, 11, is provided with a tongue 28 while the other panel, 12, is provided with a groove 30.

As can be seen, particularly in FIG. 1, the block of the prior art can be rotated about its vertical, or transverse axis and still be stackable with adjacent blocks. However, as can also be seen, if the block 10 is rotated about its horizontal, or longitudinal axis, and stacking of the block on another is attempted, the required interlocking cannot be achieved. This is due to the fact that, as described above, the tops and bottoms of the blocks are structured differently. Specifically, the result of such stacking would be either two sets of grooves or two sets of tongues abutting each other.

As also shown in FIG. 1, the panels of the blocks are provided with a plurality of projections 32 and corresponding recesses 34 on the tops and bottoms, respectively, of each panel 11, 12. The projections 32 and recesses 34 are features which serve to locate vertically adjacent blocks so as to ensure alignment of the ties 13 when the blocks are stacked. As with the tongues and grooves described above, the projections and recesses of the prior art blocks inhibit stacking if the blocks are not oriented in the same direction. It will be appreciated that the features may be provided as complementary “positive” and “negative” features formed to mate with each other. As noted in more detail below, a “positive” feature, generally, is any outward formation on the edge of the panel, while a “negative” feature, generally, is any inward formation on the edge.

FIGS. 4 to 8 illustrate an embodiment of the present invention. Referring first to FIG. 4, a foam form block 100 is shown in perspective. As can be seen, the block has some features of the prior art block discussed above and as more specifically described in U.S. Pat. No. 5,896,714 (the entire disclosure of which is incorporated herein by reference). The block 100 is comprised of a pair of foam panels 110 and 112, arranged in a parallel and opposed manner. The panels 110 and 112 are maintained a specified distance apart by means of a plurality of ties 114 extending there-between. Each block is provided with at least two ties, and preferably a plurality of ties, with each tie provided longitudinally spaced along the length of the block as is known in the art. The ties will be discussed further below.

It is notable that the panels 110 and 112 have top and bottom edges and right and left ends, each including either a tongue or groove, as will be described further below. Each of the tongues and grooves serve, as described above, to interlock the panels of one block to panels of other blocks, located vertically or horizontally adjacent thereto. It will be understood that the terms “top”, “bottom”, “right”, and “left” are used herein purely for the sake of convenience in referring to the figures and that use of such terms is not intended to mean that a block must have any particular orientation. The tongue can be viewed as a “positive” feature extending from the surface of an edge, while the groove can be viewed as a “negative” feature extending into the surface of an edge.

As shown in FIGS. 4 to 8, the top longitudinal edge 116 of panel 110 is provided with a groove 118 extending along the length of the edge 116. Groove 118 is positioned within the thickness of the panel 110. However, in other embodiments, it may be positioned anywhere across the thickness of the panel. Similarly, the bottom longitudinal edge 120 of the opposite panel 112 is also provided with a groove 122 that is identical to groove 118 in both dimensions and position along the width of panel 112.

The bottom longitudinal edge 124 of panel 110 and the top longitudinal edge 126 of panel 112 are provided with tongues 128 and 130, respectively, which extend along the lengths of the edges 124 and 126. The tongues 128 and 130 are sized and located so as to engage the grooves 118 and 122 described above, when blocks are stacked on top of each other in the process of erecting a form. For example, the tongue 128 of panel 110 would engage the groove 118 of a similar panel underneath with a similar engagement taking place between the tongue 130 of panel 112 and a groove 122 of an adjacent panel. In this manner, vertically adjacent blocks are secured together when stacked.

In order to assist in securing horizontally adjacent blocks together, the panels of the blocks are provided with a further tongue and groove structure, similar to that described above. As illustrated in FIGS. 4 to 8, the right end 132 of panel 110 is provided with a groove 134 extending the entire height of the panel. The left end 136 of panel 110 is provided with a tongue 138 being dimensioned to be received within a groove similar to 134 of a horizontally adjacent panel. Similarly, the right end 140 of panel 112 is provided with a tongue 142 while the left end 144 of panel 112 is provided with a correspondingly dimensioned groove 146. As indicated previously, the combination of tongues 138 and 142 and grooves 132 and 146 allows horizontally adjacent blocks to be engaged together.

As shown in FIGS. 4 to 8, the blocks 100 of the invention are also provided with a plurality of projections (as positive features) and recesses (as negative features), described further below, for ensuring that the ties 114 of stacked blocks are vertically aligned. Referring to FIGS. 4 to 8, the top edge 126 of panel 112 of the block 100 is provided with a plurality of projections 148. The projections 148 are preferably elongate and extend transversely from the tongue 130 to the external face of the panel 112, the external face being that surface facing away from panel 110. The projections 148 are provided in pairs, one on each side of a tie 114. The spacing between adjacent pairs of projections 148 is preferably greater than the spacing between respective projections 148 of a pair. The bottom edge 124 of panel 110 is also provided with pairs of projections 150 arranged in the same manner and having the same dimensions and positioning as projections 148.

As shown more clearly in FIGS. 5 and 8, the top edge 116 of panel 110 and the bottom edge 120 of panel 112 are, in turn, provided with recesses 152 and 154, respectively, which are adapted to receive projections 148 and 150 of vertically adjacent panels. Recesses 152 and 154 are provided in pairs, in the same manner as the projections, wherein each recess of each pair is located one on opposite sides of a tie 114. Further, as with the projections, the recesses 152 and 154 are elongate and extend from the longitudinal grooves 118 and 122, respectively, to the external faces of the panels 110 and 112.

The projections 148 and 150 are adapted to mate and to be engaged in recesses 152 and 154 when two blocks 100 are stacked above each other. For example, if a bottom block is provided in the orientation as shown in FIGS. 4 to 8, that is with the top edge 116 of panel 110 extending upwards, another block positioned above will have projections similar to projections 150 and will engage the recesses 152 of panel 110. On the other hand, if block 100 is provided with the top edge 116 extending downwards, it will be understood that the next block stacked above it will be similarly reversed in orientation. The figures illustrate projections 148 and 150 as having a tongue shape and the associated recesses 152 and 154 as having a groove shape. It will be understood that various modifications of this embodiment will be possible.

It will be noted that the features of the block 100 described above allow it to be stacked and positioned with other blocks in a form regardless of whether the “top” edges are directed upwardly or downwardly. For example, should a first block be positioned in the orientation shown in FIGS. 4 to 8, the next block can have the same orientation as the first or can be rotated so that its “top” edge points downwardly. In such case, the block would need to be rotated 180° about its vertical axis as well in order to allow the longitudinal tongues and grooves and the projections and recesses to engage one another.

In other words, in one embodiment, the panels of each block are arranged in an opposite manner with respect to each other so as to provide the block with two diagonal planes of symmetry. The first plane extends diagonally across the block from the top of one edge, through the centre, and to the bottom of the opposite edge. The second plane similarly extends from the top of one end of the block, through the centre, and to the bottom of the opposite end. This orientation allows the block to be rotated about either axis (i.e. reversible) while still being able to be stacked on another block.

As such, if on a first panel, its top edge has an arrangement of positive features on its face (e.g. one or more longitudinal tongues, one or more transverse tongues, one or more blocks, domes, nodules, pikes, poles, etc.), then on the bottom edge of that panel, there should be a complementary set of negative features on its face (e.g. depressions, gaps, grooves, indentations, notches, slots, etc.) to receive and mate with each of the positive features. It will be appreciated that there may be additional negative features on the bottom edge. For the second panel, on its top edge, there should also be a similar arrangement of complementary negative features on its face to receive and mate with each of the positive features on the top edge of the first panel. For the bottom edge of the second panel, there should be another set of positive features, as provided on the top edge of the first panel. It will be appreciated, however, in order to allow stacking of a block either in a right-side up or upside down orientation to its neighbour below, full symmetry of all positive features on the cross-corner longitudinal edges is not always necessary. On a first panel, one edge can have a set of positive features, while the cross-corner edge on the other panel needs to have only at least one of the positive features located in a mirrored location on the cross-corner edge of the other panel. As such, if the block is turned 180 degrees about its longitudinal axis, then the edge having the lesser number of positive features will still mate with the corresponding negative features in the neighbouring block.

In other embodiments, a longitudinal top edge of the first panel may have both positive and negative features. On the bottom edge of that panel, there would be a complementary arrangement of negative and positive features to mate with the corresponding opposing feature on the top edge. Meanwhile, on the second panel, the top edge would have the same complementary arrangement of negative and positive features as on the bottom of the first panel. Also, the bottom edge of the second panel would have the same arrangement of positive and negative features of the top edge of the first panel. In other embodiments, the bottom edge of the second panel would have simply at least a sufficient subset of the features of the top edge of the first panel to provide that when the block is turned 180 degrees about its longitudinal axis, the block can mate either “right-side up” or “upside-down” with another stacked block.

It will be appreciated that in one embodiment, the positive and negative features mate such that there is a reasonably tight coupling of at least some surfaces of the positive features with at least some surfaces of the negative features. However, in other embodiments, there may be a looser coupling or fitting of the positive features to the negative features, such that the negative features are larger in size than the positive features. For example, if a top edge has two or more positive features thereon, then in a loose coupling arrangement, the corresponding negative features on the bottom edge be one large feature which is sized to accept both positive features therein. In other embodiments, the positive features on one top edge of one panel may be copied on the bottom edge of the other panel. Similarly, the negative features on the bottom edge of one panel may be copied on the top edge of the other panel. In other embodiments, the features on the transverse edge of the other panel may not be a copy, but would still be of a compatible form to mate with the corresponding features of the neighbouring panel. As such, there does not necessarily have to be perfect symmetry of features from one edge of a panel to its corresponding transverse edge of the other panel. However, there should be sufficient compatibility of the features, in size, number and position such that if the form is stacked either right-side up or upside down, then the positive or negative features on the bottom edges of both panels, in either orientation, should be engaged with the corresponding features on the top edges of the panel underneath and the panel should lie flat thereagainst.

Therefore, the block of the invention is capable of being stacked over another block in either an upside-down or right-side-up orientation. This feature maximizes the number of orientations in which the block, or sections of block can be used thereby minimizing waste. For example, in some cases, a block would need to be cut to a desired length. In such cases, the portion of the block not used would normally need to be discarded since, in order to use it, a similar section of block with the same orientation of tongues/grooves would be needed. However, with a block of the present invention, the entire block or a section of the block can be rotated about either the vertical or horizontal axis and still be used in creating the concrete form.

FIG. 9 illustrates an embodiment of the ties 114 as used in the block of the invention. As shown, the ties 114 include a central, generally planar web portion 156 comprising a plurality of co-planar, intersecting members 157. As known in the art, ties 114 can be made of any type of generally rigid material and are preferably made of a plastic, such as high density polyethylene or polypropylene. The web portion has an upper end 158 and a lower end 160 as well as opposing sides 162 and 164. Each side 162 and 164 of the web portion 156 includes a flange 166. Each flange 166 comprises a generally flat element that lies perpendicular to the plane of the web 114. The flanges 166 are designed to engage the foam panels (described above). The flanges 166 are generally embedded within respective foam panels and this may be achieved by causing such foam to form around the flange or by inserting the flange into pre-cut slots in the foam panel. As indicated above, the flanges 166 preferably have a length that generally corresponds to the height of the panels 110 and 112. In this manner, the flanges 166 extend across substantially the entire height of the block 100. The web portions 156 of the ties 114 are provided with a plurality of apertures or clips 168 for receiving rebar and the like. As will be known to persons skilled in the art, rebar is used to reinforce the concrete that is provided between the panels of the block. The rebar clips 168 are either provided on or formed as part of transverse members 169 of the web 156.

As shown in FIG. 9, the web portion 158 preferably includes a line of symmetry, M, which separates the tie into two mirror image sections. This allows the tie 114 to be used in either vertical orientation. As will be noted, each of the mirror image sections includes at least two rows of rebar clips 168, the two rows being provided in a “face up” and “face down” orientation. This arrangement allows the rebar clips 168 to be easily accessible regardless of the vertical orientation chosen.

Various other features and variations of the ties 114 will be apparent to persons skilled in the art. For example, although the above embodiment has described ties that are unitary in structure, it is known, for example, for the web portion of the ties to comprise a separate piece, thereby enabling the block to be assembled on site. It is also known in the art to minimize the area occupied by the intersecting members of the web so as to reduce inhibition of concrete flow there-through. However, in other embodiments, the tie can include various other intersecting members in order to impart additional strength to the block. Further, it will be understood that the spacing between the panels of the block will depend upon the length of the web of the tie.

Referring once more to FIGS. 5 and 8, the external faces of each panel 110, 112 of the block is provided with a plurality of indicia, in the form of vertical lines or the like, to identify the locations of each tie. As known in the art, and as specifically taught in U.S. Pat. No. 5,896,714, such indicia may comprise embossing, printing, depressions, or any other such visible markings to facilitate the engagement of the protrusions (148, 150) with corresponding recesses (152, 154) and, therefore, enable stacking of blocks above each other. As mentioned above, the specific placement of protrusions and corresponding recesses serve to positively locate each block so as to align the ties. As illustrated in FIG. 3, it is preferred to stack the blocks in a staggered manner so as to avoid a continuous joint between adjacent blocks. This is a standard practice and is also taught in U.S. Pat. 5,896,714. It will be understood that to facilitate the reversibility of the block as discussed above, the indicia would preferably be provided on both panels.

FIG. 10 illustrates another embodiment of the invention, which comprises a corner block 200. As shown, the corner block 200 includes panels 210 and 212 as before. The structure of each panel is essentially the same as that of the panels 110 and 112 described above. Panels 210 and 212 include respective tongues 214, 216 and grooves 218, 220. As described above, each tongue and groove interacts with a corresponding other in vertically adjacent blocks so as to positively engage each other. The panels 210 and 212 also include respective projections 222, 224 and corresponding recesses 226, 228. Generally, the projections and recesses are provided in pairs as described above. However, in the corner portion of the corner block, additional projections 230 are provided without corresponding to ties but still serve to position vertically adjacent blocks. Further, on the inner panel 210, the corner portion is provided with only one projection 232 and recess 234 for each tie. The embodiment shown in FIG. 10 can comprise either an inside or outside corner, depending upon the positioning of the linear blocks described above. For example, the block 200 of FIG. 10 would comprise an outer corner block if the remaining blocks of the form are arranged with top directed projections (that is projections on the “top” end of the block) on the outer facing panel. If, on the other hand, the blocks of the form are arranged with the top directed projections provided on the inner facing panel, the block 200 of FIG. 10 would be used for inside corners.

It will be understood that another embodiment of the corner block, panel 210 would include top directed projections while the opposite panel 212 would include top directed recesses, which is the opposite orientation of the embodiment shown in FIG. 10.

Although the corner block of FIG. 10 is illustrated with a 90° bend, it will be understood that any desired angle can be provided.

Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. The entire disclosures of all references mentioned above are incorporated herein by reference. 

1. A reversibly stackable insulating concrete form block, for use in a concrete form system, comprising: first and second foam panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; two or more ties extending perpendicularly between said panels to maintain the panels in said spaced apart orientation; and each of said panels having top and bottom edges and left and right ends and including: a first interlocking means for engaging a respective panel of a block vertically adjacent thereto; a second interlocking means for engaging a respective panel of a block located horizontally adjacent thereto; and at least one tie aligning feature to vertically align ties of vertically adjacent blocks, wherein said panels are arranged in opposite vertical and horizontal orientation with respect to each other whereby said block can be engaged with other vertically adjacent blocks in either a right-side up or upside-down orientation.
 2. The block of claim 1 wherein said block includes a plane of symmetry extending from the top of said first panel to the bottom of said second panel.
 3. The block of claim 2 wherein said block includes a plane of symmetry extending from the top left end of said first panel to the bottom right end of said second panel.
 4. The block of claim 1 wherein said ties includes a plurality of rebar receiving clips.
 5. The block of claim 4 wherein said ties include an axis of symmetry extending transversely across the mid-point of said tie.
 6. The block of claim 1 wherein said ties include flanges embedded within each of said panels.
 7. The block of claim 6 wherein said flanges extend substantially across the height of said panels.
 8. A reversibly stackable insulating concrete form block, for use in a concrete form system, comprising: first and second foam panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; and two or more ties extending perpendicularly between said panels to maintain the panels in said spaced apart orientation, wherein each panel of said panels includes a top edge, a bottom edge, and left and right ends; for said each panel: one of said top and bottom edges includes a first tongue extending longitudinally along said edge; the other of said top and bottom edges includes a first groove extending longitudinally along said other edge and being adapted to receive a tongue having the dimensions of said first tongue; one of said left and right ends includes a second tongue extending longitudinally along said end; the other of said left and right ends includes a second groove extending longitudinally along said other end and being adapted to receive a tongue having the dimensions of said second tongue; two or more projections extending from the edge having said first tongue; and two or more recesses provided on the edge having said first groove; and said panels of said block are arranged in opposite orientation with respect to each other whereby the top of the first panel faces the bottom of the second panel and the right end of the first panel faces the left end of the second panel.
 9. The block of claim 8 wherein said block includes a plane of symmetry extending from the top of said first panel to the bottom of said second panel.
 10. The block of claim 9 wherein said block includes a plane of symmetry extending from the top left end of said first panel to the bottom right end of said second panel.
 11. The block of claim 8 wherein said projections and recesses cooperate to cause vertical alignment of said ties.
 12. The block of claim 11 wherein said ties include flanges embedded within each of said panels.
 13. The block of claim 12 wherein said flanges extend substantially across the height of said panels.
 14. A reversibly stackable insulating concrete form block, for use in a concrete form system, comprising: first and second panels, arranged opposed and parallel to each other and spaced apart by a predetermined distance; two or more ties extending perpendicularly between said panels to maintain the panels in said spaced apart orientation; on a top edge of said first panel, at least one positive feature for engaging a respective negative feature on a panel of a block vertically adjacent thereto; on a bottom edge of said first panel, at least one negative feature for receiving a corresponding positive feature of said block vertically adjacent thereto; on a bottom edge of said second panel, a compatible positive feature to each of said at least one positive feature of said first panel; and on a top edge of said second panel, a compatible negative feature to each of said at least one negative feature of said first panel, wherein said at least one positive feature, said at least one negative feature, said compatible positive feature and said compatible negative feature are located on their respective edges such that said block can be engaged with other vertically adjacent blocks in either a right-side up orientation with said at least one negative feature of said first panel engaging a corresponding positive feature on an adjacent panel of a block below said block or an upside-down orientation with said compatible negative feature of said second panel engaging said corresponding positive feature on said adjacent panel and wherein one of said at least one positive feature is a tongue extending longitudinally along said top edge. 